#include<iostream>
#include<math.h>
#define ll long long
using namespace std;
ll n,m;
ll a[107]={0,1,3,6};
int main()
{
	cin>>n;
	while(1){
		if(pow(2,m)<=n&&n<pow(2,m+1)){
			cout<<m+1<<endl;
			break;
		}
		m++;
	}
	return 0;
}
